Electrical measuring instrument



May 15, 1928.

C. OMAN ELECTRICAL MEASURING INSTRUMENT.

4 Sheets-Sheet 1 Filed Feb. 5, 1925 Fig.1.

WITNESSES:

INVENTOR Carl Oman.

, ATTORNEY May 15, 1928. 1,669,572

- c. OMAN ELECTRICAL MEASURING INSTRUMENT Filed Feb. 5, 1925 4 Sheets-Sheet 2 I7 g m 1. J 5 Wm 54 4|v A mg (D Z I WITNESSES: Q I INVENTOR Car! Oman. fl. BY

' ATTORNEY Patented May 15, 1928,

UNITED STATES PA-TENT oFFicE.

TRIO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRICAL MEASURING INSTRUMENT.

Application filed February My invention relates to electrical measuring instruments and particularly to polyphase induction meters of the watthour type. One object of my invention is to provide an instrument of the above-indicated character that shall indicate the sum of quantities in several circuits or phasesof a circuit and. be free of damping errors during the de-energization of any number of the circuits.

Another object of my invention is to provide a watthour or similar meter in which several independently operable meter ele ments shall be so mechanically connected to each other and to a common register as to eliminate certain errors occurring in instruments embodying a plurality of armature disks. 1

A further object of my invention is to provide an induction watthour meter that shall be simple and durable in construction, economical to manufacture and effective in its operation.

In polyphase watthour meters of the induction type, it has been usual to mount armature disks on a single shaft and to provide an actuating electromagnet and a damping magnet for each disk. The number of these elements required depends upon the nature of the circuit.

hen the electromagnets are energized, they produce a drag or damping effect on their respective discs, which is similar to that produced by the damping magnets. The total damping on the rotating element of the meter is the sum of this electromagnetic damping plus the permament-magnet damping and perhaps a small amount of friction. When one electromagnet is deenj ergized, its elect-ro-magnetic damping is re moved and errors are imposed on the registration of the other elements.

Accordingly, the error increases with the number of phases or circuits of which a measurement is desired and to compensate for, or to eliminate, the error becomes correspondingly increasingly difl'icult substantially in proportion to the number of added elements. In other words, while the error may be compensated for in a two-element meter by the introduction of a comparative ly simple diiierential gear mechanism be tween the two independently operable meter elements, the problem is considerably more 3, 1925. swarms 6,502.

difli'cult where three or more elements are being used.

It is my aim to overcome the above-mentioned error more particularly in connection with meters embodying several meter elements or, in other words, in connection with instruments for operation in more thantwo circuits. 5 I

In'practicing my invention, I provide a ing the inactivity of any number of the:

other elements. The mechanism is in the 'natureof superposed or compounded differential gear mechanisms of such'construction and relation as topermit the instant response of the register or indicating means to operations of all or a smaller number of the elements. I

Figure 1 oi: the accompanying drawing is atront elevationalview of a polyphase watthour meter embodying my invention,

Fig. 2 is a side'view, partially in elevation and partially in section, of the device shown in Fig. 1,

Fig. 3 is an enlarged detail plan view of the differential gear mechanism and counting register, y p

, Figs. 4 and 5 are enlarged sectional detail views of portions of thegear mechanism as shown in Fig. 3, and

Fig. 6 is a simplified or semi-diagrammatic perspective view of portions of the instrument of my invention, with the parts somewhat distorted and displaced for clearness.

- In general, the device comprises a base-1.

member 1,.a side-wall structure 2, a front cover member 3. a terminal structure 4, single-phase watt-hour meters 5, 6 and 7, a register or integrating mechanism 8, and a composite diiferential gear mechanism 10 comprising a pair of diflerential gear. mechanisms, as will hereinafter be pointed out.

The base member 1, the side-wall structure 2, the front cover member 3 and the terminal structure 4 may be of any suitable material and construction and, since they constitute no part of the invention as claimed, further. description thereof is deemed unnecessary, except to state that the meters 5, 6 and? areconnected to their cirtively.

"lhemechanisms 39 and .40, together with cuits (not shown) by terminal members 14 on the structure 4. n

The meters 5, 6 and 7 are mounted'in position on a bracket 15 that is secure'd'to rthe thes mem er :1 y -=s andards and I30, 31 and 32 rotate in accordancewith the energyexpended in. their respective circuits, further description "thereof is not deemed necessary to a full and complete understanding of the invention, as .will'hereinafter be apparent. l f

Referring more particularl to Fi s. 3,

4,. 5 and 6, in one of which tig. 6)ftie directions of rotation of the parts are indicated by arrows,'the composite differential gear mechanism 10 comprises component difl'erential gearmechani'sms 39 and 40 as shownindetail in 'Figs. 4 and 5,, respecthe integrating mechanism 8, are supported by stationary plates 41, 42 and 43'that are :held together in spaced parallel-plane rela:

tioniby cross-tie members 45 and mounted onttheibracket 15 by. screws 46.

Referring to Fi sjii and 4, ,the'mechanisni 39 comprises. a shaft 50, journaled in the plates 41 and 42, upon which a .shaftffil 1s radially fixed by a: sleeve portion52. A pinion54 isloosely" mounted on a reduced portion ,55 ot' the shaft 51-andhe1d in posi- "tion by a collar 56. A hub 59.that is loosely held in position near one end of the shaft 50 between collars 60. th at are fixed thereto,

carries agear wheel'T62 and a crown gear wheel .63 in fixed relationflto each other.

Similarly, ahub65nearthe otherend of the 1 shaft 50, is loosely "held in position thereon between a collar 66 and another hub 67 that are fixedly mounted on the shaft 50. The hub 65 carries a gear wheel'69 and a crown gear wheel 70, similar to the crown gear wheel .63, in fixed relation. to each other. Thehubz67 carries a gear wheel 71. The crown gear wheels .63 and '70 engage the pinion5j 1 on opposite sides thereof.

Ret'erring'to Figs, 3 and 5, the mechanism 40 comprisesa' shaft .75, j'ournaled 1n the plates ljand .42, upon which a shatt'ZG is radially fixed a sleeve portion 77. A

pinion 78 isloos ely mounted on a reduced portion? 9 of the shaft 76 and heldinj position'by a collar 80. A hub 83, ly held inposition near one end of the shaft that is loosebetween collars 84; that are fixed thereto,

carries a gear wheel 85 and a crown gear wheel 86 in fixed :relation to ieach other. Similarly, ahub 88 isloosely held in posttion-near the other end of the shaft 75 between collars "89 thflt are I fixed to the aha ft and carries a :gear whecl 9l andla crown gear wheel 92 in fixed relation to each other.v The crown gear-: wheels 86 and 92 engage the pinion 78. The shaft 75 further carries -a pinion 93- lixetl thereto.

Three shafts 95, 96 and 97; journaled in 'the plates 1 and 42 carry gear wheels 98,

99 and 100 engaging the gear wheels 69, 62 and 85, respectively, and dogs 103, 10 land 105, respectively, "for cooperation with dogs 106,107 and 108. g

The dog 106 is connected to the armature disk 31 of the meter 6 througha shatt109, on which thedog is mounted, a worm Wheel 110 onthe shaft109, a worm screw 112 engaging the vworinwheel 110, a shaft 114, onv which the worm screw 112 ismounted, agear wheel .115 on the shaft 114, afpinion 116 onthe shaft 117 a gear wheel 118 on pinion 120 on the,

the sl1aft117 and a shatter). I

The dog'107is connectedto the armature (.lisk30 ofthe meter 5 through a shaft'l23 on. which the dog isanounted, aworm wheel "12 l 0n the shaft 123,a wornrscrew9125 engaglng the worm wheel12 l,.a shaft 127 on which the worm screw 125 is .mounted, a gearwheel 128'on thesha'ft 127, a pinion 129 one shaft 130, agear wheel'132on the shaft 130 and apinion'133- ondthe shaft 34.,

The d0g'108 is connected to the armature Ydisk'32of the meter 7 througha shaft 136 on which the dog is mounted, a worm wheel out-he shaft 136, a worm screw L138 en gagingthe worm whee1 13.7", a'shaft 139 on which the worm screw .138 is -l1]OL111tti, a

gear wheelflltl on the shaft 139, a pinion 142on a sl1att'143, algear wheell te on the shaft 143 and a pinion 14:5 on the shaft 36.

The gear Wheel 71 on the shaft 50 engages the gear wheel91 on the hub88 to wh ch the crown gear wheel 92is also secured.

The pinion '93 which constitutes a common movable element for all of the arrrra-ture disks and is responsive tomov'ement of any number thereof, engages a, gear wheel 14:8

constituting the prlmary or initial movable element of the integrating mechanism 8.

Movement of the gear wheel148-istransmitted to a pointer 1501 through a1sha'ft149 and to polnters 151 (152 and 1 53 through success vc speed-reduction ,gear wheels a nc lfpinions 154 to 159 in ausnalfandnwellknown manner.

Inoperation,with all of the disksT30, 31

and 32 rotating inthesame direction, the movement of the disk 30 istransmitted through the, shaft 34l, the pinion 133, .the

gear wheel 132,, the shaft 130,, th pinion 129, the gear wheel 128, the shaft 127, the

worm screw 125, the worm wheel 124, the shaft 123, the dog 107, the dog 10 1, the shaft 96, the gear wheel 99, the gear wheel 62 and the hub 59 to the crown gear wheel 63 which thereby turns in the clockwise direction as viewed in the drawings.

At the same time, movement of the. disk is transmitted through the shaft, 35, the pinion 120, the gear wheel 118, the shaft 117, the pinion 116, the gear wheel .115, the shaft 114, the worm screw 112,-. the gear wheel 110, the shaft 1.09, the dog 106, the dog 103, the shaft 95, the gear wheel 98, the gear wheel 69 and the hub to the crown gear wheel 70, which thereby also turns in the clockwise direction.

Either one of the crown gear wheels 63 and 70 may be considered as stationary relative to the other, so that when one of them rotates, it will turn the pinion 54 on the other and carry the shaft 51 with the pinion 54 to rotate the shaft 50. Consequently, if the crown gear wheel 63 or 70, which is considered stationary relative to the other, also turns, as it does in this instance, the movement of the shaft 50 will be proportional to the sum of the movements of the crown gear wheels and of the meter disks 30 and 31.

This summated movement of the crown gear wheels 63 and 70 is transmitted from the shaft 50 through the hub 67, the gear wheel 71, the gear wheel 91, and the hub 88 to the crown gear wheel 92, which thereby turns in the counterclockwise direction, as indicated by the arrow in Fig. 6.

Also, at the same time, movement of the disk 32 is transmitted through the shaft 36, the pinion 1 15, the gear wheel 14: 1, the shaft 143, the pinion 1 12, the gear wheel 1 11, the shaft 139 the worm screw 138, the worm gear wheel 137, the shaft 136, the dog 108, the dog 105, the shaft 97, the gear wheel 100, the gear wheel 85 and the hub 83 to the crown gear wheel 86 which thereby also rotates in the counterclockwise direction.

As in the case of the differential gear mechanism 39, here again, either one of the crown gear wheels 86 and 92 may be considered as stationary relative to the other, so that, when one of them rotates, it will turn the pinion 78'on the other and carry the shaft 7 6 with the pinion 7 8 to rotate the shaft 75.

Consequently, when the crown gear wheel 86 or 92, which is considered stationary relative to the other, also turns, the movement of the shaft will be proportional to the sum of the movements of the crown gear wheels 86 and 92.

Thus, since the movement of the shaft 50, which is proportional tothe sum of the movements of the disks 30 and 31, .is transmitted to the crown gear wheel 92 and the movement of the disk 32 is transmitted to the crown gear 86, the movement of the shaft 75, and, consequently, of the integrating mechanism or register8 will be proportional to ltghe sum of the movements of all of the dis s. l i

When the disk 32 is stationary and the disks 30 and 31 are rotating, the crown gear -wheel 63 is stationary and the movement of the crown gear wheel 70 is transmitted by the shaft 50 to the crown gear wheel 92. Since, in this instance, the crown gear wheel 86 is also rotating, the register 8 will be actuated in accordance with the sum of the movements of the disks 31 and 32.

Similarly, with the disk 31 stationary and the others rotating or with any two disks stationary and the other rotating, the movements will be transmitted, as described, to the register 8.

Thus, the register will be actuated in accordance with the movement of any one disk, the sum of the movements of any two disks or the sum of the movements of all the disks.

Since, in contradistinction to a meter hav ing all of its disks on one shaft, the effects of each of the damping magnets 25, 26 and 27 are prevented from affecting the disks of the others, the instrument is freeffrom the objectionable damping errors referred to.

The instrument is further extremely simple in construction and flexible in its operation and, by reason of the interchangeability of its standard meter units, permits ready replacements of the same at low cost and without undue interruption of service.

While I have shown and described a particular form of my invention, various modifications may be made therein withoutrdeparting from the spirit and scope thereof as set forth in the appended claims.

I claim as my invention:

1. A'meter comprising indicating means, a differential gear mechanism, a pair of meter elements connected one to each outside gear member of said mechanism, a second differential gear mechanism and a tertiary meter element connected to one of the outside gear members of said second differential mechanism, the intermediate gear member of said first differential mechanism being connected to the other outside gear member of said second differential mechanism and said indicating means being connected to the intermediate gear member thereof.

2. In a meter, the combination with three independently-movable meter elements and a register, of a pair of differential-gear 

